What do renewable and non-renewable mean?. Energy resources can be classified into two groups. Renewable. Non-renewable. Renewable energy resources can be replaced or regenerated and will never run out (at least not for a very long time).
Energy resources can be classified into two groups.
Renewableenergy resources can be replaced or regenerated and will never run out (at least not for a very long time).
Non-renewable energy resources will eventually run out – once used they cannot be used again.
Examples: wind and solar.
Examples: coal and oil.
How many different energy resources are part of this scene?
Industrial societies need a lot of energy and, at the moment, rely on fossil fuels as the main source of this energy.
Coal, oil and natural gas are fossil fuels. They are carbon-based materials that formed over millions of years from the remains of ancient plants and animals.
Fossil fuels are so useful because they contain stored chemical energy, which is converted into large amounts of useful heat energy when the fuels are burned.
The total amount of fossil fuels available is limited and so
they are classed as non-renewable energy resources.
Power stations that are fuelled by coal and oil, operate on the same basic principle.
The fuel is burned and the heat produced is used to boil water. This creates high-pressure, superheated steam, which is then used to turn a turbine.
The turbine turns a generator and so generates electricity.
The cooling towers cool the steam, which condenses as water and can then be recycled in the power station.
Natural-gas-fired power stations do not use steam. The natural gas is burnt and the hot gases produced are used
directly to turn the turbine.
burning fossil fuels?What waste do fossil fuels produce?
Burning fossil fuels creates waste products that can act as pollutants and have harmful environmental effects.
Nuclear fuel is used to generate electricity but, unlike fossil fuels, it does not burn.
In a nuclear fuel, such as uranium, reactions take place that split the atoms and release huge amounts of heat energy.
This is called nuclear fission.
In a nuclear power station, the heat released from nuclear fission reactions is used to change water into steam. As in other types of power station, the steam then turns a turbine, which turns a generator and produces electricity.
Nuclear power stations do not release any greenhouse gases
such as carbon dioxide or gases which cause acid rain.
Nuclear power stations produce radioactive waste.
The used nuclear fuel contains some uranium, which can be separated from the waste and reused.
It also contains plutonium, which is a highly-radioactive product of the fission reactions that occur in uranium nuclear fuel.
New reactors that use this waste product as a fuel have been built.
However, plutonium is also used in the construction of nuclear bombs and poses a very serious threat if it gets into the wrong hands.
Nuclear waste that cannot be reused poses serious problems as it can remain radioactive for thousands of years.
Highly radioactive waste can be turned into glass to help stabilize it and prevent leaks during storage.
One solution is to bury the waste deep underground.
This must be in a geologically stable environment, so there are few suitable sites.
Another suggested solution is to dump radioactive waste at the bottom of the sea. Dealing with nuclear waste is
expensive and any solution has to be long term.
Type of fuel
Which type of power is useful when extra power is needed
for a short time?
The demand for electricity varies depending on the time of day and time of year. Power stations have to cope with this.
Power stations cannot be turned on at the flick of a switch. These are typical start-up times for power stations that use non-renewable energy resources.
Natural gas power stations produce electricity quickly.
Nuclear power stations take about two days to reach full power. They are only shut down for maintenance.
Time until reserves run out
about 75 years
about 300 years
thousands of yearsHow long can non-renewable energy last?
Non-renewable energy resources will eventually run out.
Scientists think that natural gas reserves will only last another 25-30 years.
It is difficult to be exact as new gas fields are still being discovered.
Even though nuclear fuel will last thousands of years, there is still a limited supply and so it will eventuallyrun out.
This is why nuclear power is classed as a non-renewable
of fossil fuels
of fossil fuelsFossil fuels: what are the pros and cons?
What are the advantages and disadvantages of burning fossil fuels in power stations to generate electricity?
low fuel cost
low building costs
short start-up times
of nuclear power
of nuclear powerNuclear power: what are the pros and cons?
What are the advantages and disadvantages of using nuclear power to generate electricity?
cheaper to run once built
expensive to build
conserves fossil fuels
produces radioactive waste
no sulfur dioxide emissions
expensive to decommission
no carbon dioxide emissions
links with cancer
safe under normal conditions
small amount of fuel used
so less transport needed
risk of disaster
by certain gases in the Earth’s atmosphere.